This application claims the benefit of Korean Application No. 12899/1997 filed on Apr. 8, 1997, and Korean Application No. 14278/1997 filed on Apr. 17, 1997, which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a computer, and more particularly, to a liquid crystal display unit of a portable computer.
2. Discussion of the Related Art
In general, a liquid crystal display(LCD) device used for a computer such as a portable computer or for a portable display is shown in FIG. 1. Referring to FIG. 1, the LCD device includes a liquid crystal panel 20, a back light unit 22, and a driving circuit board 23. The back light unit 22 is comprised of a luminescent lamp 11, a lamp housing 12 having a U-shape cross section and surrounding the lamp 11, a light guide 13, a reflector 14 reflecting the incident light from the horizontal direction to the vertical direction, a protection sheet 15 contacting the light guide 13, a first prism sheet 16 and a second prism sheet 17 set on the protecting sheet diffuser 15 and directing the incident light from the light guide 13 to specific direction, a diffuser 18 diffusing the light from the first and second prisms 16 and 17 to a viewing area 21 of the liquid crystal panel 20 with a certain viewing angle, and a first support frame 19 supporting these elements of the LCD device.
FIG. 2 shows a cross-sectional view of the light-guiding plate 13 showing a gradual decrease in thickness as the light guiding plate 13 extends away from the light source 11. A fluorescent lamp 11 as the light source is fixed at the thicker end of the light-guiding plate 13. When the fluorescent lamp 11 is turned on, the light 23 from the source 11 is reflected by the lamp housing 12 surrounding the fluorescent lamp 11. The reflected light transmits through the light guiding plate 13 towards the other side (thinner end) of the light-guiding plate 13 as indicated by the arrows. Then, the light spreads all over the surface of the light-guiding plate 13 and reaches the display area 21 (FIG. 1) through the diffusion plate 18. At the same time, a thin film transistor formed on the liquid crystal panel controls a corresponding pixel according to the signals from the driving circuit 23 (FIG. 1) to selectively transmit the light in that pixel. The same process in each pixel collecting produce the display of images on the display area 21.
The liquid crystal display is usually combined with, for example, a notebook computer for use as an output screen. The following method is used to attach the liquid crystal display to a device such as a notebook computer.
Referring to FIGS. 3a and 3b, in a conventional liquid crystal display, a ground supporting plate 30 is disposed on the first fastening frame 19. A mounting hole 33 is formed through the ground supporting plate 30 and the first fastening frame 19, as shown in FIG. 3b. Then, the ground supporting plate 30 and the first fastening frame 19 are fixed by a screw 31 as shown in FIG. 3a. In other words, a liquid crystal display is attached to a device such as a notebook computer in a manner so as to fasten the first fastening frame 19 and the ground supporting plate 30 by a fastening element such as a screw.
However, the liquid crystal display is necessarily made thicker due to the length of the screw according to the method as shown in FIGS. 3a and 3b. Moreover, since the mounting hole 33 for the screw is formed on the front surface of the liquid crystal display, the display area of the liquid crystal display must necessarily be narrowed to permit sufficient space at the margin of the front surface to accommodate mounting hole 33 and screw 31.
According to the structure described above, the LCD device operates as follows. The light from the luminescent lamp 11 is incident on the rear surface of the liquid crystal panel 20 through the back light unit 22. A control circuit placed on the driving circuit board 23 controls the incident light on the viewing area 21 of the liquid crystal panel 20 to display images and characters.
FIG. 4 is a drawing showing a plan view of the final assembly structure of the conventional liquid crystal display device. FIG. 4 also shows the assembled result of a second support frame 40, liquid crystal panel 20 and back light unit having an assembly structure for mounting to a portable computer. The second support frame 40 is made of metal or plastic, and holds the liquid crystal panel 20 and the back light unit. Here, the driving circuit board 23 is located behind the rear part of the back light unit connected to the liquid crystal panel 20 with a flexible film (not shown).
FIG. 5 shows the assembly structure of the liquid crystal panel 20 and body 60 of the portable computer in the conventional method. The second support frame 40 is mounted to a rear case 50 of the portable computer using screws 43 through screw holes 41. A front case(not shown) having a blank area adjusted to the viewing area is joined at the rear case 50. That is, the liquid crystal panel 20 is attached to the rear case 50 by the screws 43 through the screw holes the display surface in the normal direction of the surface 41 formed on. Although not shown in the drawings, the front case is mounted on the LCD device, opening the viewing area 21 and covering the other parts.
In general, as the size of the portable computer is designed for easy movement, the ratio of the viewing area to the whole surface area of the display and the thickness of the display device affects the quality of the portable computer. However, in a conventional portable computer, screw holes 41 are located on edge portions of the display surface in order to join the second support frame 40 to the rear case 50. As the display area has a screw frame area 42 (FIG. 4) for forming the holes 41, the ratio of the area of the LCD panel to the viewing area 21 is reduced.
Furthermore, in the conventional portable computer, as the screws 43 are mounted in the liquid crystal display device and the rear case 50 in the normal direction of the display surface, the display part is necessarily thick enough to form an assembly device 51 for the screws 43, such as screw holes 41. The second support frame 40 is also necessarily large enough to have a space for supporting the screw holes 41. Thus, it is difficult to reduce the weight of the portable computer.
Accordingly, a liquid crystal device is needed having a high viewing ratio of the display, low weight, and reduced thickness for a computer, such as a portable computer.
Accordingly, the present invention is directed to a computer that substantially obviates one or more of the problems due to limitations and disadvantages of the related art while retaining the advantages.
An object of the present invention is to increase the ratio of the viewing area to the whole area of a computer display.
Another object of the present invention is to provide a thin, lightweight display unit.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a liquid crystal display device comprises a liquid crystal panel including a back light unit including a light source joined with the liquid crystal panel; a first frame coupled to a surface of the backlight unit and to the sides of the liquid crystal panel; a second frame coupled to the edges of the liquid crystal panel and to the sides of the first support frame; an outer casing; and a fastening part joining together the first support frame, the second support frame, and the outer casing through the sides of the first support frame, the second support frame, and the outer casing.
In another aspect of the present invention, a portable computer comprises a liquid crystal display device having a display surface and a first plurality of side surfaces; a body having an input device; a cover, coupled to an edge of the body, having a second plurality of side surfaces; and a fastening unit attaching the first plurality of side surfaces of the liquid crystal display device to the second plurality of side surfaces of the cover, the liquid crystal display device being mounted to the cover.
In another aspect of the present invention, a portable computer comprises a liquid crystal display device having a first side surface; a body having an input device; a cover joined with the body and having a second side surface; and a fastening unit joining together the liquid crystal display device and the cover through the first and second side surfaces of the liquid crystal display device and the cover, respectively.
In a further aspect of the present invention a liquid crystal display device comprises a first support frame having a first fastening member at a side surface of the first support frame; a reflector unit adjacent the first support frame; a light source adjacent to the reflector unit; a light guide unit adjacent the reflector unit; a protection unit adjacent the light guide unit; a prism unit adjacent the protection unit; a diffuser unit adjacent the prism unit; a liquid crystal panel adjacent the diffuser unit; and a second support frame having a second fastening member at a side surface of the second support frame, wherein the reflector unit, the protection unit, the prism unit, and the diffuser unit, the liquid crystal panel are between the first and second support frame, and the first and second support frame are attached to each other through the first and second fastening members through the side surfaces of the first and second support frames.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.